Fluid pressure automatic tensioner

ABSTRACT

A tensioner, for controlling tension in winding and spooling operations of continuous strands, yarns, tows, sheets and the like, having oppositely displaceable, cooperating rolls, one of which is adapted to feel or sense tension variations in a material normally passing between the rolls and to position a fluid pressure means for applying a compensatory lesser or greater amount of tension to the material.

United States Patent 1111 3,599,300

1 7 2] Inventor Robert W. Tlmbie [56] References Cited I Pflmwhh UNlTED STATES PATENTS P 3,015,871 1/1962 Noe 28/36 1221 Filed Feb. 11,1970 1 HS] Patcmed A l7 3.440.700 4/1969 Berndge 23/36 3,481, 11 l2/l969 Norton. 1. 28/35 I 7 3 I Ass1gnee Monsanto Company St. Long, M0. Primary Examiner- Louis K Rlmrodt [S4] FLUID PRESSURE AUTOMATIC TENSIONER 9Claims,3 Diawlng Figs.

[52] U.S.Cl v v t 1 t t 1 v 28/35 [5!] Int. Cl.. ..v D02h 13/26 [50] Field Search 28/35. 36

Al|orneyx-$tanley M. Tarter, Neal E. Willis and Elmer J Fischer ABSTRACT: A tensioner, for controlling tension in wlnding and spooling operations of continuous strands, yarns. tows, sheets and the like, having oppositely displaceable cooperating rolls, one of which is adapted to feel or sense tension variations in a material normally passing between the rolls and to position a fluid pressure means for applying a compensatory lesser or greater amount of tension to the material.

PATENTED m1 1 |9T| 3599 .300

SHEET 1 OF 2 INVENTOR.

ROBERT w. TIMBIE PATENTED mm 7 zen SHEET 2 BF 2 FIG. 2.

R O T N E v W ROBERT W. TIMBIE AGENT FLUID PRESSURE AUTOMATIC TENSIONER BACKGROUND OF THE INVENTION The tensioner is described herein in association with related components of a warp sheet accumulator used in textile beaming, warping and spooling practices. In a warping Operation, a plurality of yarn ends withdrawn from creels are laced through a pair of spaced eyeboards to form a flat, horizontal warp sheet which is taken up on a warp beam. In practice, when a broken yarn end or defect is noted, it is common to reverse wind an extended length of the warp sheet from the warp beam and to store the warp sheet in an accumulator while the defect is found and corrected. To accumulate a length of warp sheet that has been wound on a beam, the warp beam is first stopped and the warp sheet is clamped or anchored at a point before delivery of the yarn ends to the accumulator. The warp beam is then run in reverse to unwind the warp sheet from the warp beam while the accumulator is operated concurrently to take up the unwound length of warp sheet. The warp sheet is taken up in an accumulator by rollers that festoon the sheet in draped folds. When the defect is corrected, the accumulated warp sheet is removed from the accumulator and unclarnped.

However, upon release of the warp sheet from its clamped condition, the warp sheet reacts similarly to a rubber band and shoots forwardly to release its stored energy and then 81(- pands and contracts vibrationally. This sudden release of the warp sheet from the clamp generally causes an entanglement of yarn ends at the eyeboards and occasional broken yarn ends and is referred to as a smashout." The tensioner embodying the invention is designed to prevent smashout situations and to control variable tension conditions in warping and similar practices.

SUMMARY OF THE INVENTKON The tensioner comprises a pair of rolls mounted on endless conveyors, belts or chains to reciprocate in opposed directions. Normally, the rolls are spread apart and have a continuous material extending therebetween.

One of the rolls is a tension sensing roll that is displaceably reciprocably within a housing linked within the endless chains.

The chain arrangement is connected to a fluid-pressure system for controlling the rotation of the chains in one or the opposite direction. The fluid pressure system is provided with switch means for starting and stopping operation of the tensioner.

When the tensioner is started, the chains are rotated to carry the sensing roll into engagement with one side of the material being processed and the other roll into engagement with the opposite side thereof. The sensing roll senses tension in the material and actuates the fluid pressure system to rotate the chains and reciprocate the rolls for taking up slack and for adding or subtracting tension applied to the material.

The tension rolls are deactivated or placed in an inoperable position out of contact of the material being processed by switching the fluid pressure system off-on control of an of position.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. I is a side elevation view of the tensioner associated with accumulator components,

FIG. 2 is a side elevation view of the tensioner as in FlG. 1, illustrating the tensioner components in an operating position, and

FIG. 3 is an end view, in perspective, of the chain and roll arrangement of the tensioner.

DESCRIPTION OF A PREFERRED EMBODlIi/IENT The tensioner is illustrated, FIG. 1, in association with accumulator components including a frame 2, a clamp 4,

eyeboards 6, accumulator rolls 8, and a driven warp beam 10.

A warp sheet 12 extends horizontally from eyeboard to eyeboard, traveling from right to left and is taken up on the warp beam 10.

The tensioner comprises a pair of endless belts or chains, 14 and 16, FIG. 2, positioned upstandingly, each at opposed sides of warp sheet 12. Chains 14 and 16 are each looped about a respective upper and lower sprocket, 18 and 20, and both upper sprockets 18 are interconnected by a shaft 22. The lower sprockets 20 are interconnected by a shaft 24, FIG. 2. For convenience of description each chain has a corresponding front span 2d and a back span 28. A pair of rolls, a roll 30 and a sensing roil 32, extend parallel and transversely across the accumulator frame 2 and each is supported at its ends on a corresponding chain span-401130 on spans 26 and roll 32 on spans 28. Sensing roll 32 has a pinion or gear 34'. mounted at each end thereof, and each pinion 34 is mounted in a respec tive toothed rack 36 which is linked within the chain span 28. Roll 30, at each end, is linked within a respective front chain span 26. Each roll, 36] and 32, is designed to be tired or rotatable according to conventional journaling practices. Preferably, a counterweight 38 is used for balancing roll 32 at a midposition in racks 36 when being used in the accumulator application illustrated. Conventionally, the counterbalance arrangement may be constructed to add or subtract weight to the sensing roll 32 to obtain desired tension.

A rod 4th, preferably adjustable, is pivotahly attached at its upper end to sensing roll 32, and is attached at its lower end to the upper end of a hydraulic cylinder &2. Cylinder 42 has a piston actuating rod 44 at its lower end that is connected to a pivotal valve handle or arm 56 of a foueway valve 48 mounted on another hydraulic cylinder 5%. Hydraulic cylinder 42 is controlled by a four-way valve $2 which is operated by an offon switch S4. in the on position switch 54 actuates a solehold to deliver fluid to the upper side of hydraulic cylinder 42 through a pipe 56 and to discharge fluid from the lower side through a pipe 53. When in an off" position the sequence is reversed. Hydraulic cylinder 42 is used in starting and stopping the apparatus only. This is explained in following description of the operation of the tensioner.

Valve 48 operates to actuate cylinder 50. Cylinder 50 reciprocates up and down on a piston actuating rod 60 that extends from the lower end of cylinder 50 and which is fixedly secured to a base 62. The upper end of cylinder 50 is attached to one end of a link 64 that is attached at its opposite end to rack 36 linked in chain 16. Through link 64 cylinder 50 rotates chains l4 and 16 in a clockwise direction, FIG. 1, when cylinder 50 descends. The chains are rotated in a counterclockwise direction when cylinder 50 elevates or rises. Valve 48 is connected to a reservoir 66 by a pipe 68. Fluid is pumped to valve 48 by a pump '70 interposed in pipe 68. When fluid is pumped to valve 48, it is also recycled, simultaneously, to reservoir 66 from valve 48 by a pipe 72. Cylinder 50 is actuated downwardly when fluid is delivered to the lower end thereof via a line 74 connected to valve 48, and is actuated upwardly when fluid is delivered through valve 48 via a line 76 to the upper end thereof. When fluid is delivered to the upper end of cylinder 50, fluid is simultaneously discharged from the lower end thereof and recycled to reservoir 66, and vice versa.

The tensioner is illustrated in the drawings in an accumulator application functioning to take up slack in the warp sheet 112 after the warp sheet i3. is released from clamp 4, FIG. 2. The tensioner then slowly releases the slack in the warp sheet thereby dampening and preventing the occurrence of a smashout condition referred to previously. Prior to describing the operation of the tensioner, assume that the warp sheet 12 is clamped within clamp d, H6. 2, and that the tensioner is in a nonoperatlng position, PM}. i. in the latter, rolls 30 and 32 are separated and disengaged from the warp sheet 12 extending therebetween. Roll 32 is in a position at the lower end of racks 36 and valve arm in is in a substantially horizontal position as shown. Assume that it is desired to release the warp sheet 12 from clamp 4. To prevent a smashout from occurring, the tensioner is put in operation. Switch 5 5 is actuated to an on position whereby fluid is delivered to pipe 56 and discharged through pipe 58. Fluid delivered to cylinder 42 actuates rod 44 downwardly, in turn rotating lever 46 in a clockwise direction a predetermined degree of rotation to position valve 48 for opening pipe 72 to line 76 discharging fluid from the upper end of cylinder 50, and connecting pipe 68 to line 74 to deliver fluid to the bottom end of cylinder 50. Cylinder 50, responsively, moves downwardly and rotates chains 14 and 16in a clockwise direction so that roll 32 is carried downwardly while roll 30 is carried upwardly. Roll 32 will continue to lower and roll 30 will rise after having contacted the warp sheet 12 until they are in the positions shown in FIG. 2. It will be noted that as roll 32 is carried downwardly by chains 14 and 16, the roll rises from the lowermost position in racks 36, FIG. 1, to the midpoint as shown in FIG. 2. In rising to the midpoint, roll 32 causes valve arm 46 to slowly rotate in a counterclockwise direction from a position below the horizontal to a horizontal position. In the horizontal position, lever arm 46 positions valve 48 to cut off flow of fluid to cylinder 50 causing the latter to stop descending and to remain in its present position thereby stopping rotation of chains 14 and 16. At this time with rolls 30 and 32 cooperating to apply a predetermined torque and tension on the warp sheet 12, clamp 4 can be unclamped to release the warp sheet 12. Roll 32 will sense any tension variations and make the proper adjustments. A predetermined rise in the dancer," floating or sensing roll 32, responsively to an increase in tension, rotates valve arm 46 of valve 48 in a counterclockwise direction to cause fluid to flow to the upper end of cylinder 51), and cylinder 50 rises until lever 46 is again in a horizontal position cutting off fluid flow to cylinder 50. if there is a decrease in tension in the warp sheet, roll 32 will descend and move valve arm 46 in a clockwise direction for opening pipe 68 to line 74 to deliver fluid to the lower end of cylinder 50 causing cylinder 50 to lower until lever 46 is horizontal again as shown in FIG. 1. Roll 32 will continue to sense tension variations in the warp sheet and compensate therefor in the manner described above,

To inactivate the tensioner, switch 54 is positioned in an off" position. Fluid is then delivered to the lower end of cylinder 42 via pipe 58 to raise rod 44 of cylinder 42, thereby rotating valve arm 46 in a counterclockwise direction and effecting a delivery of fluid to the upper end of cylinder 50 thereby operatively causing the latter to rise. As cylinder 50 rises and lifts link 64, chains 14 and 16 rotate in a counterclockwise direction moving rolls 30 and 32 away from the warp sheet to the position shown in FIG. 1. Cylinder 50 will rise until valve arm 46 is again in a substantially horizontal position.

It will he understood that the tensioner may be used in a manner similar to that described above to control tension in continuously running webs, sheets, threadlines and the like.

The fluid-pressure system may be hydraulic or pneumatic.

I claim:

1. A tensioner comprising in combination,

endless conveyor means rotatable in opposed directions,

a plurality of tension members mounted on said conveyor means,

means for mounting at At one of said tension members on said conveyor means to be independently displaceable within said conveyor means, and

fluid-pressure means connected to said conveyor means for rotating the latter, and connected to said at least one tension member for controlling operation of said fluid pres sure means.

2. A tensioner as in claim ll, further comprising switching means connected to said fluid pressure means for turning the latter off and on.

3. A tensioner as in claim 11, wherein said at least one tension member is counterbalanced.

4. A tensioncr as in claim ll, wherein said endless conveyor means comprises a pair of endless chains or belts mounted in spaced, parallel, and rotatable relation.

5. A tensioner as in claim ll, wherein said plurality of tension members comprises a pair of rolls and at least one of said rolls of said pair is a tension sensing roll connected to said fluid pressure means for sensing and compensating for variable tension conditions.

t5. A tensioncr as in claim ll, wherein said means for rnounting' at least one of said members comprises rack-andpinion means.

'7'. A tensioner as in claim ll, wherein said fluid pressure means comprises a hydraulic system having a valve control arm operatively connected to said at least one of said mem bers and mounted on a reciprocable hydraulic actuator linked to said endless conveyor means.

ii. in a textile accumulator having warp sheet festooning rolls and a clamp for clamping the warp sheet, the improvement comprising providing tension means for engaging the warp sheet and taking up the slack in the warp sheet when the latter, is released from said clamp, for sensing tension in the warp sheet and compensating therefor, and for slowly releasing the slack in the warp sheet and disengaging therefrom.

9. in a textile accumulator as in claim 8, wherein said tension means comprises,

endless conveyor means rotatable in opposed directions,

a plurality of tension members mounted on said conveyor means,

means for mounting at least one of said tension members on said conveyor means to be independently displaceable within said conveyor means, and

fluid-pressure means connected to said conveyor means for rotating the latter, and connected to said one member for controlling operation of said fluid-pressure means. 

1. A tensioner comprising in combination, endless conveyor means rotatable in opposed directions, a plurality of tension members mounted on said conveyor means, means for mounting at At one of said tension members on said conveyor means to be independently displaceable within said conveyor means, and fluid-pressure means connected to said conveyor means for rotating the latter, and connected to said at least one tension member for controlling operation of said fluid pressure means.
 2. A tensioner as in claim 1, further comprising switching means connected to said fluid pressure means for turning the latter off and on.
 3. A tensioner as in claim 1, wherein said at least one tension member is counterbalanced.
 4. A tensioner as in claim 1, wherein said endless conveyor means comprises a pair of endless chains or belts mounted in spaced, parallel, and rotatable relation.
 5. A tensioner as in claim 1, wherein said plurality of tension members comprises a pair of rolls and at least one of said rolls of said pair is a tension sensing roll connected to said fluid pressure means for sensing and compensating for variable tension conditions.
 6. A tensioner as in claim 1, wherein said means for mounting at least one of said members comprises rack-and-pinion means.
 7. A tensioner as in claim 1, wherein said fluid pressure means comprises a hydraulic system having a valve control arm operatively connected to said at least one of said members and mounted on a reciprocable hydraulic actuator linked to said endless conveyor means.
 8. In a textile accumulator having warp sheet festooning rolls and a clamp for clamping the warp sheet, the improvement comprising providing tension means for engaging the warp sheet and taking up the slack in the warp sheet when the latter is released from said clamp, for sensing tension in the warp sheet and compensating therefor, and for slowly releasing the slack in the warp sheet and disengaging therefrom.
 9. In a textile accumulator as in claim 8, wherein said tension means comprises, endless conveyor means rotatable in opposed directions, a plurality of tension members mounted on said conveyor means, means for mounting at least one of said tension members on said conveyor means to be independently displaceable within said conveyor means, and fluid-pressure means connected to said conveyor means for rotating the latter, and connected to said one member for controlling operation of said fluid-pressure means. 